Reporting Clinical Endpoints in Studies of Minimally Invasive Glaucoma Surgery

Minimally invasive glaucoma surgery (MIGS) refers to a group of procedures generally characterized by an ab interno approach, minimal trauma to ocular tissue, moderate efficacy, an excellent safety profile, and rapid recovery. The number of MIGS procedures continues to increase, and their use has become widespread among glaucoma and cataract specialists. Standardization of the methodology and reporting of clinical endpoints in MIGS investigations enhances interpretation and comparison across different studies. The assessment of surgical interventions should not only consider statistical significance, but also whether the outcome is meaningful to patients. Minimal clinically important difference (MCID) is defined as the smallest change in a treatment outcome that is considered beneficial for an individual patient and prompts a change in their clinical management, and expert consensus is an accepted approach to determine the MCID. The American Academy of Ophthalmology's Glaucoma Preferred Practice Pattern Panel is an expert panel that develops guidelines identifying characteristics and components of quality eye care. The panel recommends that the cumulative probability of surgical success at 2 years with Kaplan-Meier survival analysis be used as the primary efficacy endpoint in MIGS studies. The panel suggests that surgical success for standalone MIGS be defined as intraocular pressure (IOP) ≤ 21 mmHg and reduced ≥ 20% from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The proposed MCID for the cumulative probability of success of standalone MIGS at 2 years is 50%. The panel recommends that surgical success for MIGS combined with cataract extraction with intraocular lens implantation (CE-IOL) be defined as a decrease in glaucoma medical therapy ≥ 1 medication from baseline without an increase in IOP, or IOP ≤ 21 mmHg and reduced ≥ 20% from baseline without an increase in glaucoma medications, additional laser or incisional glaucoma surgery, loss of light perception vision, or hypotony. The suggested MCID for the cumulative probability of success for CE-IOL/MIGS at 2 years is 65%.